The use of rechargeable lithium-ion batteries is growing steadily for many applications including its use in electric vehicles (EV) and Plug-in Hybrid Electric Vehicles (PHEV). The lithium-ion battery is also being used for energy storage for electrical grid networks and many other larger scale applications. It is already the dominate battery for cell phones, laptops, and mobile electronic applications. As these batteries reach end of life there is a need to provide a satisfactory recycle and disposal procedure for them. This is particularly acute for the large size prismatic batteries which are being made for many automotive and grid storage applications. These large format batteries and the cells of which they are made contain anodes which consist of carbon coated on copper foil and cathodes consisting of expensive lithium metal oxides such as lithium cobaltate, mixed lithium nickel/manganese oxides, lithium cobaltate/manganese/nickel oxides, lithium cobaltate/nickelate and related cathode materials on aluminum foil with a polymeric binder such as Kynar®. Currently, there are two recycle processes being used for lithium ion batteries: 1) These batteries are fed into electric furnaces already containing molten steel with the contained anode reducing carbons along with the separators and with flux to enrich the forming stainless steel alloy in cobalt, nickel and/or manganese. The lithium is fluxed into the slag and may be recovered at high cost with several extra processing steps (Umicor process); 2) The batteries are processed through a hammer mill and the screened −25 mesh slurry filtered and packaged. This slurry contains about 30% metals from the cathode along with the carbon. This metal rich mixture is shipped to an electric smelter for utilization in making steels. The copper and aluminum foils are separately recovered from the process.
Although the valuable cobalt and nickel is recovered along with the manganese for scrap metal prices, the full value of the lithium metal oxide cathode material is lost and usually with no recovery of the lithium metal oxide. It would be a major improvement in the recycling of strategic materials and would lower the cost of lithium batteries if the full value of the lithium metal oxide cathode material could be achieved by complete recovery and regeneration for direct reuse in a new lithium-ion battery. In addition, almost all of the lithium would also be recovered in the cathode material and remain as part of the lithium metal oxide cathode as it is regenerated and used in the new battery.
The recovery and reuse of the cathode material would lessen pressure on supply of lithium cathode materials such as nickel and cobalt.
U.S. Pat. No. 6,818,351 to Sernagawa et al. which is herein incorporated by reference in its entirety for all purposes, discloses the preparation of a cathode which can be used with the present invention. The cathode active components are a mixture of LiCoO2 and spinel type lithium manganate.
U.S. Pat. No. 6,872,491 to Kanai et al., which is herein incorporated by reference in its entirety for all purposes, discloses the preparation of cathodes for lithium ion secondary batteries.
U.S. Patent Publication No. 2005/0260495A1 of Onnerud et al. discloses a composition having a formula LixMgNiO2 wherein 0.9<x<1.3 and 0.001<y<0.1 which can be used as cathode material. The material is prepared by a method using a plurality of heat soaking temperatures.
U.S. Pat. No. 6,818,351 to Sernagawa et al. which is herein incorporated by reference discloses the preparation of lithium secondary battery cathodes with spinel type lithium manganese oxide and lithium containing cobalt oxide.